Device, method, and computer-readable recording medium for notifying content scene appearance

ABSTRACT

An extracting unit extracts keywords from metadata extracted from played scenes. An attaching unit attaches a semantic class to the keywords. A semantic class determining unit determines whether the semantic class is a should-be-played class. When there is a keyword with the should-be-played class attached, an acquiring unit acquires at least one keyword without having the should-be-played class as a should-be-observed keyword. When the metadata includes the should-be-observed keyword and a keyword to which a should-be-stopped class is attached, an appearance determining unit determines that a scene including the should-be-observed keyword appears in contents.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2008-84604, filed on Mar. 27,2008; the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device, a method, and acomputer-readable recording medium for notifying a user that an objectof interest appears on a scene when watching a television program or anyother video contents, thereby realizing an effective viewing.

2. Description of the Related Art

Recently, television programs often make announcements such as “Xappears soon” and “Y comes on right after this” to give the viewersadvance notice regarding the appearance of an object of interest. Suchannouncements are made in an effort to keep the viewers stay with theprogram without changing the channel. Even after the announcements, itusually takes a while for the objects X and Y to actually appear ontothe scene. For this reason, the viewers may have to watch the televisionby (1) being forced to stay with unwanted scenes although the desiredscene could be very short; (2) changing the channel to view anotherprogram while frequently checking the previous channel; or (3) recordingthe program and viewing it later.

Operations (1) and (2) waste time and give the user labor of checking.As for operation (2), if the user likes the program on the channel thathas been changed to, the user may miss the scene of the desired objecton the previous channel. In operation (3), the user can view the programlater, which minimizes the risk of missing the desired scene. However,if the user wants to watch, for example, a quiz show in ease, arecording operation may give the user a burden. Furthermore, the usermay not want to record live broadcasting of a sport game or the like butsimply want to obtain in-progress game reports. With the conventionaltechnologies, the efficiency of television viewing may be reduced.

Some technologies (for example, JP-A 2005-323090 (KOKAI)) suggestmethods of detecting and notifying the viewer of a desired scene so thatthe viewer can view the scene without missing. According to the methodoffered by JP-A 2005-323090 (KOKAI), scene specifying keywords enteredby the viewer are compared with broadcast data (transport stream) inwhich scene information that identifies a scene is superimposed on eachscene of a program to detect a desired scene in the program.

The method of JP-A 2005-323090 (KOKAI), however, is predicated on thescene information that is superimposed on the broadcast data. This meansthat scene information needs to be added to every scene of every programof every broadcast station to realize the notification of any desiredscene for any program of any station, which is very difficult. In placeof scene information that identifies scenes, subtitles may beincorporated. However, subtitle information may not always accuratelyidentify scenes. Even when a keyword that indicates the object of theviewer's interest appears in the subtitles, it may take a while for theobject corresponding to the keyword to actually appear onto the scene,as previously mentioned. Therefore, in the conventional technologies,there is a possibility of notifying the viewer of a wrong scene as theone in which the object of interest actually appears when the object hasnot yet appeared.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided adevice for notifying a scene. The device includes a playing unit thatplays contents including plural scenes that can be played in timesequence; a metadata extracting unit that extracts metadata that is textinformation on the scenes from played scenes; a keyword extracting unitthat extracts keywords from the metadata; an attaching unit thatattaches a semantic class indicating a semantic attribute of a keywordto each of the keywords; a semantic class determining unit thatdetermines whether the semantic class attached to the keyword is ashould-be-played class indicating that playback is performed after ascene from which the keyword is extracted; an acquiring unit that, whenthere is a keyword to which the semantic class determining unitdetermines that the should-be-played class is attached, acquires atleast one keyword that is not provided with the should-be-played classas a should-be-observed keyword from among the keywords to which thesemantic classes are attached; an appearance determining unit that, whenthe metadata extracted from a scene that is played after a scene fromwhich the should-be-observed keyword is extracted includes theshould-be-observed keyword and a keyword to which a should-be-stoppedclass that is a semantic class indicating that playback is completed isattached, determines that a scene including the should-be-observedkeyword appears in contents that are being played; and a notifying unitthat, when the scene including the should-be-observed keyword appears,makes a notification that the scene including the should-be-observedkeyword appears.

Furthermore, according to another aspect of the present invention, thereis provided a method of notifying a scene. The method includes playingcontents including plural scenes that can be played in time sequence;extracting metadata that is text information on the scenes from playedscenes; extracting keywords from the metadata; attaching a semanticclass indicating a semantic attribute of a keyword to each of thekeywords; determining whether the semantic class attached to the keywordis a should-be-played class indicating that playback is performed aftera scene from which the keyword is extracted; acquiring, when there is akeyword to which the semantic class determining unit determines that theshould-be-played class is attached, at least one keyword that is notprovided with the should-be-played class as a should-be-observed keywordfrom among the keywords to which the semantic classes are attached;determining, when the metadata extracted from a scene that is playedafter a scene from which the should-be-observed keyword is extractedincludes the should-be-observed keyword and a keyword to which ashould-be-stopped class that is a semantic class indicating thatplayback is completed is attached, that a scene including theshould-be-observed keyword appears in contents that are being played;and notifying, when the scene including the should-be-observed keywordappears, that the scene including the should-be-observed keywordappears.

Moreover, according to still another aspect of the present invention,there is provided a computer-readable recording medium that storestherein a computer program for notifying a scene. The computer programcauses a computer to execute playing contents including plural scenesthat can be played in time sequence; extracting metadata that is textinformation on the scenes from played scenes; extracting keywords fromthe metadata; attaching a semantic class indicating a semantic attributeof a keyword to each of the keywords; determining whether the semanticclass attached to the keyword is a should-be-played class indicatingthat playback is performed after a scene from which the keyword isextracted; acquiring, when there is a keyword to which the semanticclass determining unit determines that the should-be-played class isattached, at least one keyword that is not provided with theshould-be-played class as a should-be-observed keyword from among thekeywords to which the semantic classes are attached; determining, whenthe metadata extracted from a scene that is played after a scene fromwhich the should-be-observed keyword is extracted includes theshould-be-observed keyword and a keyword to which a should-be-stoppedclass that is a semantic class indicating that playback is completed isattached, that a scene including the should-be-observed keyword appearsin contents that are being played; and notifying, when the sceneincluding the should-be-observed keyword appears, that the sceneincluding the should-be-observed keyword appears.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram for showing the structure of a scene notifyingdevice according to an embodiment of the present invention;

FIG. 2 is a diagram for showing an example data structure of dictionaryinformation stored in a dictionary storage unit;

FIG. 3 is a diagram for showing another example data structure of thedictionary information stored in the dictionary storage unit;

FIG. 4 is a flowchart of the entire monitor information extractingprocess according to the embodiment;

FIG. 5 is an example of subtitle information that is superimposed onvideo contents and distributed to viewers;

FIG. 6 is an example of keywords to which semantic classes are attached;

FIG. 7 is a diagram showing an example display screen presentingshould-be-observed information;

FIG. 8 is a diagram showing another example display screen presentingshould-be-observed information;

FIGS. 9A and 9B are flowcharts of the entire scene notifying processaccording to the embodiment;

FIG. 10 is a diagram showing an example method of notifying the viewerof the appearance of a scene;

FIG. 11 is a diagram showing another example method of notifying theviewer of the appearance of a scene;

FIG. 12 is a diagram showing still another example method of notifyingthe viewer of the appearance of a scene; and

FIG. 13 is a diagram for explaining a hardware structure of the scenenotifying device according to the embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of a device, a method, and a program of thepresent invention are explained in detail below with reference to theattached drawings.

The scene notifying device according to the present embodiment extractstext information metadata from a scene of contents; picks up, from amongkeywords in the metadata, keywords placed before or after a keyword towhich a semantic class indicating near future is attached; anddetermines the picked-up keywords as keywords that are to be observed(should-be-observed keywords). When a should-be-observed keyword isdetected in a scene played later than the scene from which the metadatais extracted, and also when there is, before and after theshould-be-observed keyword, any keyword to which a semantic classindicating a past tense or a present perfect tense is attached, it isdetermined that the object corresponding to the should-be-observedkeyword shows up.

In the structure of FIG. 1, a scene notifying device 100 includes aplaying unit 101, a metadata extracting unit 120, a dictionary storageunit 131, a keyword extracting unit 102, an attaching unit 103, asemantic class determining unit 104, a should-be-observed informationacquiring unit 105, a should-be-observed information storage unit 132, adisplaying unit 106, a receiving unit 107, an appearance determiningunit 108, and a notifying unit 109.

The playing unit 101 plays contents containing plural scenes, such as atelevision broadcast. It should be noted that the contents are notlimited to television broadcasts and that any types of contents can beincorporated as long as metadata for each of the scenes included in thecontents can be extracted as text information. For example, videocontents stored in a recording medium such as a digital versatile disk(DVD) and audio contents such as a radio broadcast may be incorporated.In the following explanation, playback of video contents distributed asa television broadcast is used as an example.

The metadata extracting unit 120 extracts metadata for each scene of thevideo contents distributed through television broadcasting from abroadcast wave of the video contents. The metadata extracting unit 120includes an attached-information extracting unit 121, an imagerecognizing unit 122, and an audio recognizing unit 123.

The attached-information extracting unit 121 extracts, as metadata,attached-information that is text information such as an electronicprogram guide (EPG), a data broadcast, and subtitles that aresuperimposed on the television broadcast video contents.

The image recognizing unit 122 recognizes image information, such as aperson and a building, and telops in the video contents, and extracts,as metadata, text information representing the recognized imageinformation and telops.

The audio recognizing unit 123 recognizes audio information contained inthe video contents, such as utterance, music, and sound effects, andextracts, as metadata, text information representing the recognizedutterance, the title of the music piece, or the type of sound effects.

The dictionary storage unit 131 stores therein dictionary informationthat is used to acquire a semantic class indicating the semanticattribute of a keyword contained in the metadata. As shown in FIG. 2,the dictionary information includes keywords, the semantic classes ofthe keywords, and the certainty factors of the semantic classes thatindicate the certainty of the semantic classes. The semantic classesinclude time-associated classes such as near future, past, and presentperfect, name-associated classes such as names of physical entities suchas people and places, and exaggeration-associated classes.

The dictionary information is referred to when the keyword extractingunit 102, which will be discussed later, extracts a keyword from themetadata or when the attaching unit 103, which will also be discussedlater, attaches a semantic class to the extracted keyword.

The data structure of the dictionary information is not limited to thestructure illustrated in FIG. 2, but any data structure can be adoptedfor the dictionary information as long as the semantic classes ofkeywords in the text information of the metadata or the like can bedetermined by use of the dictionary information. In the example of FIG.3, the dictionary information includes conditions defining rules forarrangements of character strings and morphemes, semantic classes, andcertainty factors that are brought into association with one another.With such dictionary information, a keyword that satisfies a conditioncan be extracted from given text information, and also a semantic classthat corresponds to the extracted keyword can be attached to theextracted keyword.

The keyword extracting unit 102 extracts from the extracted metadata akeyword that matches one of the keywords in the dictionary informationstored in the dictionary storage unit 131. The keyword extraction is notlimited to this method, but the structure may be such that the metadatais morphologically analyzed so that a keyword obtained as a result ofthe analysis is extracted.

The attaching unit 103 attaches a corresponding semantic class of thedictionary information to each of the keywords extracted by the keywordextracting unit 102.

The process in which the keyword extracting unit 102 extracts thekeywords from the metadata and the attaching unit 103 attaches asemantic class to each of the extracted keywords is the same asexecution of a metadata semantic analyzing process. The semanticanalyzing process may be conducted by finding a match from among givenkeywords as illustrated in FIG. 2, or by finding a match from amonggiven conditions as illustrated in FIG. 3.

For a keyword that has multiple meanings, different semantic classes maybe acquired from the dictionary information. For example, “Kawasaki” canbe a name of a person and a name of a place. In such a case, all theacquired semantic classes can be used as they are. However, for the sakeof the user's convenience, it is preferable to narrow down to onesemantic class by choosing either the semantic class with the greatestcertainty factor or the semantic class closest to the semantic classesof adjacent keywords.

The semantic class determining unit 104 determines whether there is,among the keywords extracted by the keyword extracting unit 102, anykeyword to which a semantic class of should-be-played indicating theplayback performed after the keyword-extracted scene is attached. Forinstance, the should-be-observed information acquiring unit 105determines whether there is any keyword to which a semantic classindicating near future is attached as a should-be-played class.

When it is determined that there is a keyword to which theshould-be-played class is attached among the extracted keywords, theshould-be-observed information acquiring unit 105 acquires keywordsplaced before and after the keyword of interest as should-be-observedkeywords. Furthermore, the should-be-observed information acquiring unit105 acquires the semantic classes of the acquired keywords before andafter the keyword of interest as should-be-observed classes. In thefollowing explanation, the should-be-observed keywords andshould-be-observed classes may be referred to as should-be-observedinformation.

In other words, the should-be-observed information acquiring unit 105can acquire not only keywords but also semantic classes as targets underobservation. This realizes accurate notification of a desired scene. Forinstance, when a message “big actor coming up soon” is output, theconventional technology allows for detection of a scene on which akeyword “big actor” appears, but not a scene on which the name of theactor actually appears. In contrast, according to the presentembodiment, the semantic class “big actor” can be observed. Thus, ifthere is any dictionary information item that indicates a name of aperson associated with the semantic class “big actor”, a scene on whichthis name actually appears can be detected.

It should be noted that the should-be-observed information acquiringunit 105 acquires, as should-be-observed keywords, any keywords otherthan the selected keyword from among the keywords extracted from onescene. The should-be-observed information acquiring unit 105 may beconfigured in such a manner as to analyze the modification relation ofthe keywords extracted from a scene and acquire keywords having amodification relation with the selected keyword as should-be-observedkeywords.

The displaying unit 106 displays the should-be-observed informationacquired by the should-be-observed information acquiring unit 105 toinquire about whether to actually put the should-be-observed informationunder observation. An example of the display screen showing theshould-be-observed information will be discussed later.

The receiving unit 107 receives a keyword designated by the user bychecking the display screen so that the keyword would be put underwatch. For example, the receiving unit 107 receives, from among thedisplayed should-be-observed keywords, a should-be-observed keywordselected with a remotely controlled cursor.

The should-be-observed information storage unit 132 stores therein thedesignated should-be-observed information received by the receiving unit107. The should-be-observed information storage unit 132 associatesidentification information of the target video contents such as achannel ID of a television broadcast with the should-be-observedinformation, in such a manner as (should-be-observed keyword, channelID) and (should-be-observed class, channel ID).

The dictionary storage unit 131 and the should-be-observed informationstorage unit 132 may be realized by any recording medium that iscommonly used, such as a hard disk drive (HDD), a magneto-optical (MO)disk, a memory card, and a random access memory (RAM).

The appearance determining unit 108 determines whether theshould-be-observed information stored in the should-be-observedinformation storage unit 132 appears in the contents that aresequentially played. More specifically, the appearance determining unit108 determines whether the metadata extracted from a scene played afterthe storage operation of the should-be-observed information includes theshould-be-observed information, and also whether a should-be-stoppedclass that is a semantic class indicating the completion of playback isattached to the keywords placed before and after the should-be-observedinformation. When the metadata extracted from a scene played after thestorage operation of the should-be-observed information includes theshould-be-observed information, and also when a should-be-stopped classis attached to the keywords placed before and after theshould-be-observed information, the appearance determining unit 108determines that a scene containing the should-be-observed informationappears. For the should-be-stopped class, a semantic class indicating apast or present perfect tense may be adopted.

More specifically, when the should-be-observed information is ashould-be-observed keyword, the appearance determining unit 108determines whether the keywords in the metadata extracted from theplayed scene include the should-be-observed keyword and also whether theshould-be-stopped class is attached to the keywords before and after thekeyword that matches the should-be-observed keyword. When theshould-be-observed information is a should-be-observed class, theappearance determining unit 108 determines whether the keywords in themetadata extracted from the played scene include a keyword to which theshould-be-observed class is attached and also whether theshould-be-stopped class is attached to the keywords before and afterthis keyword to which the should-be-observed class is attached.

The notifying unit 109 notifies the user that a scene containing theshould-be-observed information appears when the appearance determiningunit 108 made the determination. For example, the notifying unit 109displays a scene containing the should-be-observed information on thedisplaying unit 106 to notify the viewer of the appearance of the scene.The manner of the notifying unit 109 making a notification will bedescribed later.

The should-be-observed information extracting process performed by thescene notifying device 100 configured in the above manner according tothe present embodiment is explained below with reference to FIG. 4. Inthe should-be-observed information extracting process, theshould-be-observed information is extracted from the contents that arebeing played and stored in the should-be-observed information storageunit 132.

The should-be-observed information extracting process is initiated when,for example, the user starts viewing a television broadcast. First, whenthe broadcast video contents are played, the attached-informationextracting unit 121 of the metadata extracting unit 120 extracts, asmetadata, attached-information distributed in such a manner as to besuperimposed on the video contents such as an EPG, data broadcast, andsubtitles (Step S401).

In FIG. 5, an example of subtitles for a conversation about an iguanabroadcasted on a certain channel between the times 21:28:00 and 21:30:00is provided.

In FIG. 4, the image recognizing unit 122 recognizes the image of everyscene of the video contents, and extracts therefrom as metadata, textinformation of a person, a building, or a telop obtained as a result ofthe recognition (Step S402). Furthermore, the audio recognizing unit 123recognizes the audio information contained in the video contents, andextracts therefrom as metadata, text information of an utterance, thetitle of a music piece, or a type of sound effects obtained as a resultof the recognition (Step S403).

The operations at Steps S401 to S403 do not have to be performed in thisorder. The processes may be performed in any order, or in parallel.

Next, the keyword extracting unit 102 extracts keywords from theacquired text information (metadata) (Step S404). For example, thekeyword extracting unit 102 extracts, from the metadata, a keyword thatmatches one of the keywords included in the dictionary information asshown in FIG. 2.

Then, the attaching unit 103 attaches a semantic class to each of theextracted keywords (Step S405). For example, the attaching unit 103acquires a semantic class that corresponds to an extracted keyword fromthe dictionary information as shown in FIG. 2, and attaches it to thekeyword.

FIG. 6 is a diagram showing a list of keywords with semantic classesattached thereto, which is obtained as a result of a semantic analysisof the subtitle information of FIG. 5 by use of the dictionaryinformation. In FIG. 6, to the keywords “Yamamoto-san” and “Shima-san”,which are considered to be names of the people who are in the program, asemantic class “person, celebrity” is attached. To the keywords “iguana”and “lizard”, a semantic class “animal, reptile” is attached.

In FIG. 4, the semantic class determining unit 104 determines whetherthere is any keyword to which a semantic class “time, near future” isattached (Step S406). When there is any (Yes at Step S406), theshould-be-observed information acquiring unit 105 acquires, asshould-be-observed keywords, keywords placed before and after thekeyword to which the semantic class “time, near future” is attached,and, as should-be-observed classes, the semantic classes attached tothese keywords (Step S407).

Next, the should-be-observed information acquiring unit 105 determineswhether the acquired should-be-observed information (should-be-observedkeywords or should-be-observed classes) has been stored in theshould-be-observed information storage unit 132 (Step S408). When noshould-be-observed information is yet stored (No at Step S408), theshould-be-observed information acquiring unit 105 provides the user withthe acquired should-be-observed information (Step S409). Theshould-be-observed information acquiring unit 105 may present theshould-be-observed information on the display screen of the displayingunit 106 to provide the user with the acquired should-be-observedinformation.

In FIG. 7, an example of should-be-observed information 701 displayedbeneath the video contents is illustrated. The displaying manner is notlimited to this, and the should-be-observed information may be displayedin any other position on the screen.

In the example of FIG. 7, a keyword 712 (“answer”) placed before akeyword 711 (“after commercials”) to which a semantic class indicatingthe should-be-played, “time, near future”, is attached is acquired as ashould-be-observed keyword. In addition, a semantic class “intangibleobject” attached to this should-be-observed keyword is acquired as ashould-be-observed class. The acquired should-be-observed keyword andshould-be-observed class are displayed as the should-be-observedinformation 701. The black square placed in front of theshould-be-observed keyword in this drawing indicates that theshould-be-observed keyword (“answer”) in the should-be-observedinformation is designated by the user. Then, the should-be-observedkeyword associated with the channel ID, “(answer, channel 4)”, is storedin the should-be-observed information storage unit 132.

In FIG. 4, the receiving unit 107 determines whether the user designatesthe should-be-observed information to put under observation (Step S410).When the user has designated (Yes at Step S410), the receiving unit 107receives the designated should-be-observed information, and stores it inthe should-be-observed information storage unit 132 (Step S411).

When it is determined at Step S406 that there is no keyword to which thesemantic class “time, near future” is attached (No at Step S406), whenit is determined at Step S408 that the should-be-observed informationhas been stored in the should-be-observed information storage unit 132(Yes at Step S408), when it is determined at Step S410 that the user hasnot designated the should-be-observed information to put underobservation, or after the should-be-observed information is stored atStep S411, the playing unit 101 determines whether the playback of thevideo contents is completed (Step S412).

When it is not completed (No at Step S412), the playing unit 101continues the playback of the video contents. Thereafter, the systemreturns to Step S401, where the process is repeated by extractingmetadata from a newly played scene. When the playback of the videocontents is completed (Yes at Step S412), the should-be-observedinformation extracting process is terminated.

The should-be-observed information extracting process may be performedonly when a predetermined action, such as the user's pressing a certainbutton on a remote control, is conducted. In this manner, theshould-be-observed information is displayed only when the user desires.

When a different action, such as the user's pressing a different button,is executed, the should-be-observed information extracting process maybe configured in such a manner that keywords and their semantic classesobtained at the time of execution of the action are extracted asshould-be-observed information, regardless of the presence of a keywordto which the semantic class “time, near future” is attached.

FIG. 8 is a diagram for showing an example of the display screenpresenting the should-be-observed information with the above structure.In response to the pressing of a remote control button, the keyword 811(“ANIME”) and the keyword 812 (“FAN”) are acquired as should-be-observedkeywords. Furthermore, the semantic classes attached to theseshould-be-observed keywords, “product” and “status”, are acquired asshould-be-observed classes. The acquired should-be-observed keywords andshould-be-observed classes are displayed as should-be-observedinformation 801. When the keyword “ANIME” is designated, theshould-be-observed keyword is brought into association with the channelID, as a result of which “(ANIME, channel 6)” is stored in theshould-be-observed information storage unit 132.

The scene notifying process performed by the scene notifying device 100according to the present embodiment is explained below with reference toFIGS. 9A and 9B. In the scene notifying process, a scene in which theshould-be-observed information appears is detected from the contentsplayed after the should-be-observed information is stored, and the sceneis notified of.

In the same manner as in the should-be-observed information extractingprocess, viewing of video contents such as a television broadcast isused as an example in the following explanation. However, any othertypes of contents may be incorporated as long as metadata for a scenecan be extracted as text information.

First, the metadata extracting unit 120 determines whether theshould-be-observed information is stored in the should-be-observedinformation storage unit 132 (Step S901). When no should-be-observedinformation is stored (No at Step S901), it means that there is nothingto should-be-observed. Thus, the scene notifying process is terminated.

When the should-be-observed information is stored (Yes at Step S901),the metadata extracting unit 120 extracts metadata from the videocontents corresponding to a broadcast wave of the channel ID associatedwith the should-be-observed information (Steps S902 to S904).

The metadata may be extracted in parallel from all the broadcast wavesof the channel IDs that can be received in a certain region. If thedevice does not have a sufficient metadata extracting capability, thenumber of targets under observation may be limited by displaying awarning message such as “no more targets under observation entered”.

The metadata extracting process at Steps S902 to S904 and the semanticanalyzing process at Steps S905 and S906 are the same as Steps S401 toS405 of the should-be-observed information extracting process. Thus, theexplanation thereof is omitted.

After the semantic analyzing process, the appearance determining unit108 compares the keyword extracted in the semantic analyzing process orthe semantic class attached to this keyword with the should-be-observedinformation that is stored in the should-be-observed information storageunit 132 and includes a should-be-observed keyword or ashould-be-observed class (Step S907).

Then, the appearance determining unit 108 determines whether theextracted keyword or the semantic class of the keyword matches theshould-be-observed information in the should-be-observed informationstorage unit 132 (Step S908). When they do not match (No at Step S908),the metadata extracting process is repeated for the subsequently playedscene (Step S902).

When there is a match (Yes at Step S908), the appearance determiningunit 108 further determines whether the semantic class of the keywordextracted at a position before or after the extracted keyword is “time,past” or “time, present perfect” (Step S909).

In the example of FIG. 7, the keyword 712 (“answer”) is stored as ashould-be-observed keyword. Supposing that a scene to which subtitles orvoice indicating “the answer has been . . . ” is attached is played, akeyword “answer” that matches the should-be-observed keyword and akeyword “has been” that follows this keyword are extracted from thescene. The keyword “has been” is given the semantic class “time, presentperfect” that indicates the completion of playback in accordance withthe dictionary information of FIG. 3, for example. Thus, the appearancedetermining unit 108 determines that the semantic class of the keyword“has been” that follows the keyword that matches the should-be-observedkeyword is “time, present perfect”.

If the semantic class is neither “time, past” nor “time, presentperfect” (No at Step S909), the metadata extracting process is repeatedfor the subsequently played scenes (Step S902). This is because thetarget indicated by the should-be-observed information is not consideredto have appeared in the video contents.

If the semantic class is “time, past” or “time, present perfect” (Yes atStep S909), the appearance determining unit 108 determines that thetarget indicated by the should-be-observed information has appeared.Then, the appearance determining unit 108 determines whether the channelID of the target under observation associated with theshould-be-observed information matches the channel ID of the channel nowbeing viewed (Step S910).

When the channel IDs do not match (No at Step S910), the notifying unit109 notifies the user that a scene containing the should-be-observedinformation appears (Step S911). According to the present embodiment, anotification is given to the user only when the should-be-observedinformation appears in the metadata of the broadcast contents and when akeyword to which the semantic class indicating the completion ofplayback “time, past” or “time, present perfect” is attached is placedbefore or after the should-be-observed information.

The notifying method performed by the notifying unit 109 is explainedbelow. FIGS. 10 to 12 are diagrams for showing examples of methods withwhich the notifying unit 109 notifies the viewer of a scene.

In FIG. 10, at the bottom of the display screen on the channel currentlybeing viewed, a message that a desired scene appears on a differentchannel (“a topic regarding ANIME starts on channel 6”) is displayed.

FIG. 11 is a diagram for showing another notifying method with whichvideo of a target under observation on a not-viewed channel is displayedat the lower right corner of the display screen on the channel currentlybeing viewed. According to the notifying methods of FIGS. 10 and 11, thenotification of the appearance of the target under observation can bemade without interrupting the user's viewing the contents on a channel.

In the example of the notifying method of FIG. 12, the target underobservation is notified of by automatically switching to the video ofthe channel on which the target under observation appears. The user canthereby effectively view the scene in which the target under observationappears, without missing it.

The structure may be configured in such a manner that the user canselect a notifying method by presetting it on the system, or that theuser can select one when setting a target under observation. Otherwise,the structure may be configured in such a manner that notifying methodsare switched around in correspondence with the certainty factor of thesemantic class.

In FIGS. 9A and 9B, after the notifying unit 109 notifies the user thatthe scene appears (Step S911), the receiving unit 107 determines whetherthe user designates the termination of the observation (Step S912). Thetermination of the observation may be determined in accordance with thepressing of a specific button of the remote control.

When the termination of the observation is not designated (No at StepS912), it means that a desired scene has not yet appeared. Thus, thesystem goes back to Step S902 to continue the observation. When thetermination of the observation is designated (Yes at Step S912), theappearance determining unit 108 deletes the correspondingshould-be-observed information from the should-be-observed informationstorage unit 132 (Step S913). Thereafter, the system goes back to StepS901. After determining whether any other should-be-observed informationitem is stored, the process is repeated.

When it is determined at Step S910 that the channel IDs match (Yes atStep S910), it means that the user is currently viewing the target underobservation. The notifying unit 109 therefore does not make anotification. Then, the appearance determining unit 108 deletes thecorresponding should-be-observed information from the should-be-observedinformation storage unit 132, and the system goes back to Step S901 torepeat the process.

The scene notifying device according to the present embodiment notifiesthe user of a scene when the should-be-observed information is detectedin the metadata of the broadcast contents and only when ashould-be-stopped class containing the semantic class of a tense such aspast and present perfect is attached to a keyword placed before or afterthe should-be-observed information. As a result, a notification is notmade when coming-up messages are repeatedly displayed but the targetunder observation has not yet appeared, while a notification is suitablymade when the target actually appears.

The appearance of the target under observation is determined not only bycomparing keywords but also by using semantic classes for targets underobservation. Thus, even when, for example, a message “big actor comingup right after this” is output, a desired scene can be suitably detectedand notified of to the user. With conventional technologies usingkeywords only, it has been difficult to realize such scene detection.

Finally, the hardware structure of the scene notifying device accordingto the present embodiment is explained with reference to FIG. 13.

The scene notifying device according to the present embodiment has ahardware structure using a regular computer, including a control devicesuch as a central processing unit (CPU) 51, storage devices such as aread only memory (ROM) 52 and a RAM 53, a communication interface (I/F)54 connected to a network to perform communications, external storagedevices such as an HDD and a compact disc (CD) drive, a display device,input devices such as a keyboard and a mouse, and a bus 61 connectingthese components.

A scene notifying program executed by the scene notifying deviceaccording to the present embodiment is stored and provided in acomputer-readable recording medium such as a compact disk read onlymemory (CD-ROM), a flexible disk (FD), a compact disk recordable (CD-R),and a digital versatile disk (DVD) in a file of an installable orexecutable format.

The scene notifying program executed by the scene notifying deviceaccording to the present embodiment may be stored in a computerconnected to a network such as the Internet and downloaded via thenetwork. The scene notifying program executed by the scene notifyingdevice according to the present embodiment may be provided ordistributed via a network such as the Internet.

The scene notifying program according to the present embodiment may bestored in a ROM in advance and provided in this manner.

The scene notifying program executed by the scene notifying deviceaccording to the present embodiment has a module structure including theabove units (the playing unit, the metadata extracting unit, the keywordextracting unit, the attaching unit, the semantic class determiningunit, the should-be-observed information acquiring unit, the receivingunit, the appearance determining unit, and the notifying unit). As anactual hardware structure, the CPU 51 (processor) reads the scenenotifying program from the recording medium and executes the program sothat the units are loaded and generated on the main storage device.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. A device for notifying a scene, comprising: a playing unit that playscontents including plural scenes that can be played in time sequence; ametadata extracting unit that extracts metadata that is text informationon the scenes from played scenes; a keyword extracting unit thatextracts keywords from the metadata; an attaching unit that attaches asemantic class indicating a semantic attribute of a keyword to each ofthe keywords; a semantic class determining unit that determines whetherthe semantic class attached to the keyword is a should-be-played classindicating that playback is performed after a scene from which thekeyword is extracted; an acquiring unit that, when there is a keyword towhich the semantic class determining unit determines that theshould-be-played class is attached, acquires at least one keyword thatis not provided with the should-be-played class as a should-be-observedkeyword from among the keywords to which the semantic classes areattached; an appearance determining unit that, when the metadataextracted from a scene that is played after a scene from which theshould-be-observed keyword is extracted includes the should-be-observedkeyword and a keyword to which a should-be-stopped class that is asemantic class indicating that playback is completed is attached,determines that a scene including the should-be-observed keyword appearsin contents that are being played; and a notifying unit that, when thescene including the should-be-observed keyword appears, makes anotification that the scene including the should-be-observed keywordappears.
 2. The device according to claim 1, wherein when there is akeyword to which the semantic class determining unit determines that theshould-be-played class is attached, the acquiring unit acquires thesemantic class of at least one keyword to which the semantic class isattached but the should-be-played class is not attached, as ashould-be-observed class that is a semantic class to be observed, whenthe metadata extracted from the scene that is played after the scenefrom which the should-be-observed keyword is extracted includes akeyword to which the should-be-observed class is attached and a keywordto which the should-be-stopped class is attached, the appearancedetermining unit determines that a scene that includes a keyword of asemantic attribute indicated by the should-be-observed class appears inthe contents that are being played, and when it is determined that thescene that includes the keyword of the semantic attribute indicated bythe should-be-observed class appears, the notifying unit makes thenotification that the scene that includes the keyword of the semanticattribute indicated by the should-be-observed class appears.
 3. Thedevice according to claim 1, further comprising a dictionary storageunit that stores therein dictionary information of keywords and semanticclasses associated with one another, wherein the keyword extracting unitextracts a keyword that matches a keyword in the dictionary informationstored in the dictionary storage unit from the metadata, and theattaching unit attaches a semantic class corresponding to the keyword ofthe dictionary information that matches each of extracted keywords toeach of the extracted keywords.
 4. The device according to claim 3,wherein the dictionary information further includes certainty factors ofthe semantic classes associated with the keywords and the semanticclasses, and the attaching unit attaches a semantic class having amaximum certainty factor among the semantic classes associated with thekeywords of the dictionary information that match the extracted keywordsto each of the extracted keywords.
 5. The device according to claim 1,further comprising a dictionary storage unit that stores thereindictionary information of conditions that keywords satisfy and semanticclasses associated with one another, wherein the keyword extracting unitextracts a keyword that satisfies a condition in the dictionaryinformation stored in the dictionary storage unit from the metadata, andthe attaching unit attaches a semantic class associated with thecondition satisfied by an extracted keyword to the extracted keyword. 6.The device according to claim 5, wherein the dictionary informationfurther includes certainty factors of the semantic classes, and theattaching unit attaches a semantic class having a maximum certaintyfactor from among the semantic classes corresponding to a condition thatthe extracted keyword satisfies to the extracted keyword.
 7. The deviceaccording to claim 1, wherein the keyword extracting unit extractskeywords that appear in the metadata in a predetermined format, and theattaching unit attaches a semantic class predetermined in correspondencewith the predetermined format to each of the keywords.
 8. The deviceaccording to claim 1, further comprising: a displaying unit thatdisplays acquired should-be-observed keywords; and a receiving unit thatreceives designations of the acquired should-be-observed keywords,wherein when the metadata that is extracted from a scene played afterthe scene from which the should-be-observed keywords are extractedincludes a should-be-observed keyword for which the designation isreceived and the keyword to which the should-be-stopped class isattached, the appearance determining unit determines that the sceneincluding the should-be-observed keyword appears in the contents thatare being played.
 9. The device according to claim 1, wherein theplaying unit plays the contents including the scene to which themetadata is attached, and the metadata extracting unit extracts themetadata attached to the scene from the scene.
 10. The device accordingto claim 1, wherein the playing unit plays video contents that includesthe scenes, which are image information, and the metadata extractingunit extracts text information obtained as a result of recognizing theimage information as the metadata.
 11. The device according to claim 1,wherein the playing unit plays video contents including the scenes,which are image information, and audio information that corresponds tothe image information, and the metadata extracting unit recognizes theaudio information and extracts text information obtained as a result ofrecognition as the metadata.
 12. The device according to claim 1,wherein the playing unit plays audio contents including the scenes,which are audio information, and the metadata extracting unit extractstext information obtained as a result of recognition of the audioinformation, as the metadata.
 13. A method of notifying a scene,comprising: playing contents including plural scenes that can be playedin time sequence; extracting metadata that is text information on thescenes from played scenes; extracting keywords from the metadata;attaching a semantic class indicating a semantic attribute of a keywordto each of the keywords; determining whether the semantic class attachedto the keyword is a should-be-played class indicating that playback isperformed after a scene from which the keyword is extracted; acquiring,when there is a keyword to which the semantic class determining unitdetermines that the should-be-played class is attached, at least onekeyword that is not provided with the should-be-played class as ashould-be-observed keyword from among the keywords to which the semanticclasses are attached; determining, when the metadata extracted from ascene that is played after a scene from which the should-be-observedkeyword is extracted includes the should-be-observed keyword and akeyword to which a should-be-stopped class that is a semantic classindicating that playback is completed is attached, that a sceneincluding the should-be-observed keyword appears in contents that arebeing played; and notifying, when the scene including theshould-be-observed keyword appears, that the scene including theshould-be-observed keyword appears.
 14. A computer-readable recordingmedium that stores therein a computer program for notifying a scene, thecomputer program causing a computer to execute: playing contentsincluding plural scenes that can be played in time sequence; extractingmetadata that is text information on the scenes from played scenes;extracting keywords from the metadata; attaching a semantic classindicating a semantic attribute of a keyword to each of the keywords;determining whether the semantic class attached to the keyword is ashould-be-played class indicating that playback is performed after ascene from which the keyword is extracted; acquiring, when there is akeyword to which the semantic class determining unit determines that theshould-be-played class is attached, at least one keyword that is notprovided with the should-be-played class as a should-be-observed keywordfrom among the keywords to which the semantic classes are attached;determining, when the metadata extracted from a scene that is playedafter a scene from which the should-be-observed keyword is extractedincludes the should-be-observed keyword and a keyword to which ashould-be-stopped class that is a semantic class indicating thatplayback is completed is attached, that a scene including theshould-be-observed keyword appears in contents that are being played;and notifying, when the scene including the should-be-observed keywordappears, that the scene including the should-be-observed keywordappears.